Wide bandwidth infrared detector and imager

Abstract

An apparatus and method for a detector are disclosed. The apparatus disclosed contains an extractor layer, an absorber layer disposed adjacent to the extractor layer, a first electrical contact and a second electrical contact. The absorber layer is configured to absorb photons of incident light and generate minority electrical carriers and majority electrical carriers. In the disclosed apparatus, the top surface of the absorber layer is shaped as a pyramid, the extractor layer is electrically connected with the absorber layer and with the first electrical contact for extracting the minority electrical carriers, and the absorber layer is electrically connected with the extractor layer and with the second electrical contact to extract the majority electrical carriers.

1. A detector comprising:
 an extractor layer; 
 an absorber layer disposed adjacent to the extractor layer; 
 a first electrical contact; and 
 a second electrical contact, 
 wherein the absorber layer is configured to absorb photons of incident light and generate minority electrical carriers and majority electrical carriers; 
 wherein the top surface of the absorber layer is shaped as a pyramid, the extractor layer is electrically connected with the absorber layer and with the first electrical contact for extracting the minority electrical carriers, and the absorber layer is electrically connected with the extractor layer and with the second electrical contact to extract the majority electrical carriers. 
 
     
     
       2. The detector of  claim 1 , wherein the absorber layer is disposed above the extractor layer. 
     
     
       3. The detector of  claim 2 , further comprising a base layer disposed between the extractor layer and the absorber layer, wherein the base layer is composed of the same material as the absorber layer. 
     
     
       4. The detector of  claim 1 , wherein the height of the pyramid is 50% or more of the height of the absorber layer. 
     
     
       5. The detector of  claim 1 , further comprising a read-out integrated circuit configured to process signals from the first electrical contact and the second electrical contact. 
     
     
       6. The detector of  claim 2 , further comprising a metal pad adjacent to the extractor layer, wherein the metal pad is configured to reflect incident light into the absorber layer. 
     
     
       7. The detector of  claim 6  further comprising, dielectric buffer separating the absorber layer and the metal pad. 
     
     
       8. The detector of  claim 1 , Wherein the top surface of the absorber layer is shaped as a plurality of pyramids disposed adjacent to each other. 
     
     
       9. The detector of  claim 8 , further comprising a plurality of extractor layers, wherein each pyramid in the plurality of pyramids is disposed directly above one of the extractor layers in the plurality of the extractor layers. 
     
     
       10. The detector of  claim 9 , further comprising a plurality of electrically interconnected contacts, wherein each contact in the plurality of electrically interconnected contacts is electrically connected with one of the extractor layers in the plurality of the extractor layers. 
     
     
       11. The detector of  claim 1 , wherein the extractor layer is disposed above the absorber layer. 
     
     
       12. The detector of  claim 1 , wherein the extractor layer is an apex of the pyramid. 
     
     
       13. The detector of  claim 12 , wherein the first electrical contact is disposed above the extractor. 
     
     
       14. The detector of  claim 1 , wherein the second electrical contact is an apex of the pyramid. 
     
     
       15. The detector of  claim 1 , wherein shape of the pyramid's base is square, rectangular, hexagon, triangular, circular, or elliptical. 
     
     
       16. The detector of  claim 1 , wherein the absorber layer comprises lightly doped n-type material or p-type material. 
     
     
       17. The detector of  claim 1 , wherein the extractor layer comprises p-type material and the absorber layer comprises n-type material, or the extractor layer comprises n-type material and the absorber layer comprises p-type material. 
     
     
       18. The detector of  claim 1 , wherein the bottom surface of the absorber layer is shaped as a second pyramid. 
     
     
       19. The detector of  claim 18 , wherein the height of the pyramid is different from the height of the second pyramid. 
     
     
       20. The detector of  claim 8 , wherein the bottom surface of the absorber layer is shaped as a second plurality of pyramids disposed adjacent to each other. 
     
     
       21. The detector of  claim 13 , further comprising a top electrical interconnect electrically connected with the first electrical contact, wherein the top electrical interconnect defines openings that pass a substantial portion of photons of incident light to the absorber layer. 
     
     
       22. The detector of  claim 14 , further comprising a top electrical interconnect electrically connected with the second electrical contact, wherein the top electrical interconnect defines openings that pass a substantial portion of photons of incident light to the absorber layer. 
     
     
       23. The detector of  claim 1 , further comprising a passivation layer substantially covering the surface of the absorber layer, wherein the passivation layer is configured to prevent dark current due to surface states and carrier recombination at those surface states. 
     
     
       24. The detector of  claim 8 , wherein the bases of the pyramids in the plurality of pyramids are at a predetermined distance from each other. 
     
     
       25. The detector of  claim 8 , wherein the bases of the pyramids in the plurality of pyramids are configured to provide a path between the pyramids for the flow of the minority electrical carriers and/or the majority electrical carriers generated by the absorber layer. 
     
     
       26. The detector of  claim 8 , the second electrical contact is disposed between two of the adjacent pyramids in the plurality of pyramids. 
     
     
       27. A method of detecting incident light, the method comprising:
 providing an absorber layer shaped as a pyramid and configured to reduce reflection of an incident light and absorb the photons of the incident light and generate minority electrical carriers and majority electrical carriers; and 
 providing an extractor layer for extracting the minority electrical carriers. 
 
     
     
       28. A method of manufacturing a detector, the method comprising:
 providing a substrate; 
 forming an extractor layer above the substrate; 
 forming an absorber layer above the extractor layer; 
 etching the absorber layer to form one or more pyramidal shapes; 
 providing a carrier substrate; 
 joining the carrier substrate with the absorber layer; 
 removing the substrate; 
 patterning the extractor layer to a predetermined shape; 
 forming one or more first metal contacts electrically contacted with the extractor layer; and 
 forming one or more second metal contacts electrically contacted with the absorber layer. 
 
     
     
       29. A method  claim 28 , further comprising:
 connecting the one or more first metal contacts and the one or more second metal contacts with a read-out integrated circuit; and 
 removing the carrier substrate.